1. Field of the Invention
The present invention relates to a cartridge-type gas grill commonly referred to as a “cassette grill”, and more particularly, to a structure for providing safety to a gas grill (twin burner type gas grill) including, for example, two gas containers and two gas flow paths reaching two burners.
2. Description of the Prior Art
In Japan, in conformity to the rules regarding product safety of gas devices, twin burner type gas grills as described above are structured so as not to discharge gas unless two gas containers are loaded, in order to guarantee safety. Therefore, when, for example, one of the gas containers in use becomes empty and is detached in order to be replaced with another gas container, an open/close valve located in a flow path for providing gas to a burner corresponding to the other gas container which still has gas therein is closed and thus the fire is extinguished.
However, if the new gas container is connected in this state, there is an undesirable possibility that gas leaks from the burner corresponding to the other gas container for which the open/close valve is opened when the new gas container is connected.
In order to avoid this, a safety device as disclosed in Patent Document 1 has been proposed.
This safety device has the following structure so that when one of the open/close valves is opened or when a gas container is detached in the state where one of the open/close valves is opened, another gas container cannot be connected in such a state. The safety device includes a spring, a pin or the like for preventing the connection. In addition, shafts of two, namely, left and right, operation knobs are associated with each other, so that when the shaft of one of the operation knobs is rotated in a direction of closing the valve, the rotation is transmitted to the shaft of the other operation knob. This structure using, for example, the spring, the pin or a helical spring for the associated operation is a mechanical structure.
Patent Document 1 describes that such a structure prevents a gas container with certainty from being connected in the state where gas may leak. It is also described that when one of the operation knobs is closed, the other operation knob is also closed, and therefore, inadvertent gas leak is prevented.